This invention relates to a semi-automatic paper insertion apparatus for a printer, typewriter, etc.
Heretofore, an electronic typewriter has been provided with a semi-automatic paper insertion apparatus in some applications, and U.S. Pat. No. 4,266,880 discloses one type of paper insertion apparatus, for example, in which the paper bail is movable between two stable positions or a position in which it is in contact with the platen and a position in which it is moved away from the platen, so that the paper feed drive source can be actuated when the paper bail is moved away from the platen, to start feeding of paper.
Besides the aforesaid type of paper feeding operation, a skew correcting operation should be performed, for example, when the paper bail is located in a position in which it is moved away from the platen. When the skew correcting operation is performed, the paper feed drive source is actuated as the paper bail is moved away from the platen. Thus the paper bail might interfere with other necessary operations and trouble might be caused. Also, when paper insertion is effected by moving the paper bail away from the platen, paper feed is effected by simultaneously setting a desired printing initiating position in this condition, so that when the feeding of paper covers a large distance there might be the risk that the paper fed might not move along the platen and catch at its leading end against the inner surface of the cover.
In another type of paper insertion apparatus, means is provided for moving the pressure rollers into and out of contact with the platen so as to perform the operation of moving the pressure rollers and the paper bail into and out of contact with the platen by a single lever linking the paper bail to the pressure rollers. In this type of apparatus, it would be impossible to move the pressure rollers away from the platen while the paper bail is kept in contact with the platen, by actuating the lever to effect switching. The result of this would be that it would be impossible to use a page feeder including sprocket apertures formed on opposite sides of the paper and sprocket wheels engaging the sprocket apertures.